A number of projection systems designed to render images, or more specifically, an image frame, by successively turning on and off selected ones of a number of solid state light emitting devices have been proposed. In a projection system, such use of light emitting devices as illumination sources presents different design challenges than the use of a projector lamp as an illumination source. The light emitting devices are typically pulsed on and off in a rapid manner, whereas projector lamps typically remain constantly on throughout operation. Light emitting devices, such as light emitting diodes, typically exhibit a high sensitivity to spurious fluctuations in driving current. This high sensitivity to spurious fluctuations in driving current may result in unintended light output from the light emitting device, resulting in artifacts in the images ultimately rendered by the projection system.
The many design challenges of using light emitting devices in a projection system, only a few of which have been briefly discussed, will require skilled design of light emitting device driver circuits. As the use of light emitting devices, such as light emitting diodes, continues to expand, driver circuits for light emitting devices in other demanding applications will likely make use of driver circuits designed for the demanding application of image projection.